This paper examined whether the intrinsic fluorescence of epidermal cells collected from touch surfaces could be used to discern contributor cell populations in a biological mixture.
The goal of this study was to survey intrinsic fluorescence of epidermal cells collected from touch surfaces and investigate whether this property could potentially be used to discriminate between contributor cell populations in a biological mixture. Analysis of red autofluorescence (650-670nm) showed that some contributors could be distinguished on this basis. Variation was also observed between autofluorescence profiles of epidermal cell populations from a single contributor sampled on different days. This dataset suggests that red autofluorescence may be a useful marker for identifying distinct cell populations in some mixtures. Future efforts should continue to investigate the extrinsic or intrinsic factors contributing to this signature, and to identify additional biomarkers that could complement this system. Interpretation of touch DNA mixtures poses a significant challenge for forensic caseworking laboratories. Front end techniques that facilitate separation of contributor cell populations before DNA extraction are a way to circumvent this problem. (Published Abstract Provided)